Battery backup question

cemmerts · Oct 13, 2020

I’m looking for a battery backup for my return pump and I have a couple questions for someone more knowledgeable than myself. I’m trying to figure out the ice cap vs Ecotech vs UPS.

will the Ecotech work with a current USA 24vEflux return pump? Can multiple Ecotechs be put together in series? I’m estimating about 9hrs of battery with a 24v 20w draw?

For the UPS, I worry about size and being so close to an area where some salt water could potentially splash onto it.

thanks!

Silent · Oct 13, 2020

UPS is inefficient. Watch some BRS videos on those. Ecotech is not for current usa. You should not mix 24v with 12v.
Your best bet or I should say least expensive DIY way to do it is 2 automotive batteries in series (12v + 12v = 24v). There are so many great youtube videos on this. They last a long time compared to other options.

chipmunkofdoom2 · Oct 13, 2020

UPSs work, they're just a really expensive way to get what is basically an AC/DC inverter, transfer switch and charger all in one package. An Ecotech battery would probably not work as the batteries are 12V and your return pump is 24V.

The best solution is probably to DIY a direct DC to DC system. This will be the cheapest and give you the best run times, but requires the most DIY and electrical experience. You can do it with one 12V battery and a voltage booster to get 24V output. You'll probably want to incorporate a relay so that your return isn't running through the battery system all the time, although you certainly could do that if you floated the battery and got a powerful enough 12V power supply.

Next best thing would probably be an inverter/charger. This is probably the easiest in terms of electrical knowledge, but it's more expensive and you sacrifice some choice in terms of components. It's also not as efficient as direct DC to DC. This is like a UPS in that it's an AC/DC inverter, transfer switch, and battery charger all in one. The only difference is it doesn't include the battery and there are lots out there, so you can size the system however you want.